At an Indian Head house party July 7, 2012, 18-year-old Gilchrist of Cheltenham allegedly was involved in an altercation with 23-year-old Marco Deangelo Sawyer of Waldorf. Sawyer threw one punch, witnesses said, and that single punch was enough to kill Gilchrist.

A jury trial for Sawyer, who is charged with manslaughter, second-degree assault and affray, began Monday afternoon in front of Circuit Judge Amy Bragunier.

“One punch. One from the defendant sent Jerry Gilchrist to his death,” Charles County Deputy State’s Attorney Karen Piper said Monday afternoon during her opening statement. At the party, Piper said, Sawyer and another man, 20-year-old Kyrel Antonio Lewis of Mechanicsville, confronted Gilchrist during the party at a point when several fights were going.

“At some point in time, pockets of fights broke out ... and [Saywer and Lewis] connected with Jerry, threw one punch and knocked him out forever,” Piper said.

Lewis faces the same charges but is not scheduled to stand trial until next month, according to court records.

In his opening, Sawyer’s defense attorney Michael Beach took issue with the ambiguity of Piper’s statements.

“The one thing that is ... a foreshadowing of things to come is [Piper] said, ‘They connected’ with [Gilchrist] after saying it was one punch,” Beach said. “[Sawyer] isn’t just presumed innocent. He is innocent. This case is a tragedy, but it would be a tragedy for the wrong person to be convicted.”

Beach told the jury to anticipate “anger, guilt ... a motive to blame” Sawyer from the witnesses for the prosecution, saying their argument is “built on shaky, unreliable eyewitnesses.”

Although she only testified briefly, Gilchrist’s mother Floriece took the stand to establish that her son had just graduated from high school and was working as a pool manager at Joint Base Andrews when he went to the party that night.

Erica Capuano, who attended the party that night, knew Sawyer and Lewis, and testified that some months before that night, Sawyer had been flirting with her via text message despite his being in a relationship at the time. When Capuano denied his advances and threatened to show his girlfriend the messages, she testified that Sawyer threatened to “blow her brains out through the back of her head.”

The party, Capuano said, began quietly enough but quickly grew out of control. Capuano described seeing “a lot of craziness and fights and arguing” going on outside the Indian Head home, although she was unsure what started it. Capuano was hit in the head with a rock by a girl who was flinging them about, she said. At one point, she testified to hearing gunshots fired.

Following that, Capuano said she ran back inside with many of the other partygoers but returned outside just as the big fight involving Gilchrist, Sawyer and Lewis was getting underway.

Capuano testified to seeing Sawyer throw one punch, hitting Gilchrist and sending him to the ground. At that point, Capuano said, she went over to Gilchrist to try and help him.

“[Gilchrist] just dropped flat on his back, and that was it,” Capuano said in her testimony. “He gasped for breath, but after that stopped, that was it. There was no gasping, no more sound. He didn’t just look unconscious. He really looked lifeless.”

Capuano also testified to seeing Sawyer get in another altercation with a different partygoer that night.

The trial was suspended Tuesday, as Bragunier could not be present, and was expected to resume today.